【7月】半双工方案总结.ppt

1、Concurrent cooperation of half- and full-duplex terminals in future multi-hop FDD based cellular network,This paper shows how half-duplex terminals should be operated to achieve the same performance as full-duplex terminals. 2. solve the problem of the coordination of half- and full-duplex terminal

2、operation by the base station . 3. propose the resource scheduling algorithm located in the MAC layer 4.discusses implications and performance results especially for throughput and delay to compare the half and full duplex in single and multi-hop cellular networks . 5. Discuss the resource schedulin

3、g and throughput of Integrate half-duplex FDD in parallel to full-duplex FDD in future cellular multi-hop mobile radio networks,it is shown that a well chosen resource scheduler and partitioning, together , can provide an equal and fair service to all terminal classes. The resource scheduler must co

4、nsider the capabilities and actual availability of terminals for UL/DL transmission as well as the actual “role” of the relay stations,FDD full and half duplex operation for 3GPP-LTE,There are two half-duplex groups, say 1 and 2. UTs belonging to the group 1 receive in the first half of a frame and

5、transmit in the second half whereas UTs of group 2 do it the other way round.,Problem: unfair resource distribution between the two groups .group 1 gets fewer resources on the DL than group 2 because of RM,Solution1: This can lead to a waste of resources, if a few terminals operate in half-duplex FD

6、D mode. The different groups RM should be different ,which cause the resource waste,Solution2：（ to reduce unfair resource distribution ） Frame N duplex group 1 would receive the resource map and in frame N+1 group 2 receives the map each group receives a resource map every other frame and both chunk

7、s in a frame belong to the same group,Relay Nodes (RN) are useful to extend the coverage area of a BS in a cost-efficient way or to increase the throughput capacity of a cell, but increase the complexity of half-duplex scheduling. RNs behave like a UT towards the BS and behave towards their UTs like

8、 a BS. During the BS phase ,the RN schedules UTs of the associated half-duplex Groups ,while during the UT phase , it is scheduled by the BS to receive the resource map. RNs are supposed to operate in full-duplex mode , so the link between RN and BS is full-duplex communication whereas the link betw

9、een RN and UT is half-duplex. The “BS” and “UT” phase finish a whole transmission from UT to BS ,which is the same time to get the next RM for UT ,the mean ,a time of frame.,The arrows point to the frames that are scheduled during the RM phases.,The gross calculated throughput of DL and UL,DL throug

10、hput for scenario 1and 2,The actual maximum throughput is lower than the analytically calculated one the maximum achievable throughput for the full-duplex terminal is twice as high as for the half-duplex terminal. The multi-hop systems DL throughput curve is twice as the single-hop, but the curve is

11、 similar to each other,DL throughput for scenario 3, one BS and two UTs,The upper curve, which shows the sum of the values of both terminals, is nearly the same as the full-duplex maximum throughput in scenario 1, obviously the maximum capacity of the cell The sum of both terminals reaches a maximum

12、 net throughput of about 84 MBit/s whereas the gross calculations added up to about 98 MBit/s with an overhead of about 12%. Full- and half-duplex UTs reach their saturation at about 63MBit/s and 21MBit/s . The saturation value for the full-duplex terminal (middle curve) is as expected exactly three

13、 times as high as the one for the half-duplex terminal (lower curve), because the half-duplex terminal gets half of all resources every second frame and no resources at all the other frame.,DL delay for scenario 3, one BS and two UTs,1. In the low traffic cases the delay is constant, nearly the same

14、 for half- and full-duplex terminals 2. as soon as the full-duplex terminal demands more resources, the delay for the half-duplex terminal increases. 3. The delay for the full-duplex terminal increases not until the saturation throughput is reached,DL throughput for scenario 4, one BS, three RNs and

15、 twelve UTs,The results show the last scenario where the influences of single-hop and multi-hop, half- and full-duplex terminals on each other The scenario consists of one BS and three RNs each of them serving one full-duplex and two half-duplex terminals belonging to different half-duplex groups th

16、e full-duplex terminal now gets only twice as much resources as the half-duplex terminals , for the two half-duplex . 15.4MBit/s full-duplex single-hop 7.7MBit/s half-duplex single-hop 5.2MBit/s full-duplex multi-hop 2.6MBit/s half-duplex multi-hop The total throughput is （multi-hop data has to be s

17、ent twice）(15.4+7.7*2)+(5.2+2.6*2)*3*2=93.2MBit/s Compare with the scenario 3, the total is closer to the gross calculations 98MBit/s,Reliable Full-Duplex File Transmission over Half-Duplex Telephone Lines,Propose a scheme for achieving reliable duplex transmission over a half-duplex communication T

18、he purpose of this article is to describe an adequate scheme for both the detection and correction of transmission errors over a half-duplex telephone line. This is a difficult problem due to the necessity of sending control, error, and verification information over the same noisy line. The adequate

19、 scheme used two bits of control information (verify and alternation bits) per message while the inadequate scheme used only one bit (the acknowledge bit).,To each message sent from A to B we attach an extra bit called the alternation bit. This bit is of course subject to the error checking. After B

20、 receives the message it decides if the message had no errors (is error-free). It sends back to A a verification message (verify bit) indicating to A whether or not the immediately preceding A to B message was error-free. After A receives this verification one of three possibilities holds: (1) the A

21、 to B was good, (2) the A to B message was bad, (3) the verification was in error so that A does not know whether the A + B message was good or bad. In cases (2) and (3) A simply resends the same A to B message as before. In case (1), A fetches the next message to be sent, and sends it, inverting th

22、e setting of the alternation bit with respect to the previous A to B message.,Comparison of Full-Duplex and Half-Duplex Modeswith a Fixed Amplify-and-Forward Relay,In various channel conditions, how to choose the best selection of full- and half-duplex ? The step of solving the problem: for a given

23、loop interference power , we first quantify the capacity ratio of the two modes. Then we evaluate the maximum loop interference power which allows higher capacity with the full-duplex mode than with the half-duplex mode.,The selection between the full-duplex and the half-duplex modes has no influenc

24、e in various mobile relays except for fixed infrastructure-based relays this problem Our discussion indicates that the full-duplex mode is an attractive choice for fixed relays provided that the loop interference power is maintained at a tolerable level. When comparing to the half-duplex mode, the f

25、ull-duplex mode has higher capacity in practical channel conditions. the full-duplex mode can tolerate high loop interference power while achieving the same capacity as the half-duplex mode.,Two-hop full-duplex relay link with loop interference.,the instantaneous end-to-endsignal-to-interference and

26、 noise ratio (SINR),the average end-to-endcapacity with the half- and full-duplex mode,full-duplex: half-duplex: (elimination of loop interference and the half of the capacity ),From the formulation of capacity ,which is determined by the rSR and rRD , the value in the fig.2 is,we separate the compa

27、rison of the full-duplex and half-duplex modes into two cases according to the definition of the loop interference power 1. the loop interference power is defined relatively to the relay input noise power. 2.it is defined relatively to the desired signal power in the relay input.,CASE1,CASE2,CONCLUSION,CASE1: the full-duplex mode achieves better capacity than the half-duplex mode irrespective of the channel SNRs, if the power of the loop inte